Golf club

ABSTRACT

A golf club with an enhanced degree of freedom in design as well as high efficiency. A head  2  is formed by combining two different metallic components. One is a head body  11  having a hosel  3 , made from stainless steel such as SUS 304 that is easy to process, the other is a face plate  14  made from nickel beryllium alloy which is an expensive metal of high strength. These two components are joined to each other by laser beam welding. Thus, the inclination angle of the hosel  3  made from SUS 304 stainless steel or the like, i.e., the relative angle of the axis of a shaft  4  to the face  5  can be easily controlled, so that the loft/lie angle of a head also can be controlled easily. Further, due to the high strength of the face plate  14 , the flight distance of ball can be elongated.

BACKGROUND OF THE INVENTION

[0001] a) Field of the Invention

[0002] The present invention relates to a golf club, having a head with a shaft connected therewith.

[0003] b) Prior Art

[0004] It is known art to provide a high-performance golf club by constructing a head, with suitable combination of a plurality of different metals. For example, Japanese Un-Examined Utility Model Publication No.53-19475 discloses a golf club in which different metals are combined together, using screw fastening, while Japanese Un-Examined Utility Model Publication No.63-16065 teaches the use of press-fitting for that purpose.

[0005] Constructing a golf club head by combining a plurality of different metals enables the control of the position of the center of gravity of the head, by utilizing the difference in specific gravity between the metals. Further, whilst a high performance material is expensive in general, if a golf club head is constructed by combining plural different metals, then such high performance material is able to be used in limited areas only, so that the costs can be reduced.

[0006] According to the above-mentioned prior art which combines a plurality of different metals, using screw fastening or press-fitting for plastic processing, however, there would occur some problems described below: First, configurations and dimensions of components prior to being joined together are subject to too much limitation, so that the degree of freedom in designing a golf club head is lowered, thus leading to difficulties in providing a high-performance golf club head. Secondly, as some materials are not suitable for press-fitting due to their inherent natures, they can not be processed by plastic processing, and thus the kinds of useable materials are limited in the case that the plastic processing is employed. Thirdly, screw fastening requires tapping in advance, while press-fitting requires taper rolling, and thus the steps therefor and/or time for such processing is increased. The fourth problem is that plastic processing by press-fitting or the like generally results in inconstant configurations, associated with the deformation caused by the processing. The fifth problem is that a clearance is liable to be formed between joining faces, thus resulting in inferior appearance and difficult post-process.

SUMMARY OF THE INVENTION

[0007] Accordingly, it is a main object of the present invention to provide a golf club with a larger degree of freedom in designing the same, enabling the using of high-performance material only in a limited portion as well as the freely controlling of the center of gravity of the club head.

[0008] To attain the above objects, there is provided, in accordance with a first aspect of the invention, a golf club having a head with a shaft connected thereto, wherein said head is constructed by combining at least two components each of which being made from a different metal, said components being joined together by welding.

[0009] According to the above-structure, as the two or more kinds of metals are combined to form a golf club head, it is possible to use a high-performance material only in limited areas of the head, and then to control the center of gravity of the head, taking advantage of the difference in specific gravity between the metals.

[0010] Further, from a second aspect of the invention, there is provided a golf club having a head with a shaft connected thereto, wherein said head is constructed of a head body with a face and a face plate corresponding to the face, wherein said head body and said face plate are made from different metals, respectively, and are joined together by welding.

[0011] With the structure thus made, it is possible to make a high-strength face, and the center of gravity can be controlled easily.

[0012] Further, from a third aspect of the invention, there is provided a golf club having a head with a hosel and a shaft connected with the hosel, wherein said head is constructed of a head body and a separate hosel member, corresponding to said hosel, wherein said head body and said hosel member are made from different metals, respectively, and are joined together by welding.

[0013] With the structure thus made, it is possible to easily adjust the angle of the hosel member to the head.

[0014] Further, from a fourth aspect of the invention, there is provided a golf club having a head with a shaft connected thereto, wherein said head is constructed of a head body with a face and a separate balance weight, said head body and said balance weight being made from different metals, respectively, and joined together by welding.

[0015] According to the structure, it is possible to adjust the position of the center of the gravity of the head, using the balance weight which is integrally fixed to the head body by welding.

[0016] Further, from a fifth aspect of the invention, there is provided a golf club having a head with a shaft connected thereto, wherein said head is constructed by combining at least two components each of which being made from a different metal, said components being joined together by laser welding, using a laser processing machine.

[0017] According to the structure, it is possible to easily fix two or more kinds of metals, using the laser processing machine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other objects, features and advantages of the invention will be apparent to those skilled in the art from the following description of the preferred embodiments of the invention, wherein reference is made to the accompanying drawings, of which:

[0019]FIG. 1 is a section of a golf club according to a first embodiment of the invention.

[0020]FIG. 2 is an exploded perspective view showing the first embodiment of the invention.

[0021]FIG. 3 is a section of a golf club according to a second embodiment of the invention.

[0022]FIG. 4 is an exploded perspective view showing the second embodiment of the invention.

[0023]FIG. 5 is a section of a golf club according to a third embodiment of the invention.

[0024]FIG. 6 is an exploded perspective view showing the third embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0025] Hereinafter will be described embodiments of the invention with reference to the attached drawings.

[0026] Referring to FIGS. 1 and 2 showing a first embodiment of the invention, reference numeral 1 designates a golf club 1 which consists of a golf club head 2 (hereinafter called head 2) and a shaft 4 linked to a hosel 3 of the head 2. The head 2 has a face 5 formed on a front, the aforesaid hosel 3 formed on a top of a first side of the head 2, a heel 6 formed on a lower part thereof, a top 7 formed on a top of a second side of the head 2, and a sole 8 formed on a bottom thereof, respectively. The head 2 has two or more metallic materials combined together which are then joined to one another by welding.

[0027] In the first embodiment of the invention, a head body 11 made from stainless steel such as SUS304 is formed with a stepped portion 12 on its front surface, said stepped portion 12 being opposing to the face 5, formed with a window opening 13 which penetrates through a rear surface 11A. Then, a face plate 14 made from nickel beryllium alloy is fitted into the stepped portion 12 and welded thereto.

[0028] Next, a method for manufacturing the head 2 will be described.

[0029] First, SUS304 stainless steel or the like is forged to form the head body 11 provided with the hosel 3. The stepped portion 12 and window opening 13 of the head body 11 are formed by for example forging, machining or grinding. The aforesaid face plate 14 is formed by forging nickel beryllium alloy. Thereafter, the face plate 14 is fitted into the stepped portion 12, and then a processing head 15 of a laser processing machine is brought close to a boundary between the stepped portion 12 and the face plate 14 to irradiate the same with laser beam, thereby securely fixing them together, through a laser welding portion 16.

[0030] In the foregoing manufacturing method, the nickel beryllium alloy was welded to the SUS304 stainless steel with the output of the laser processing head 15 being set at 1,400 W, and the feed speed thereof at 900 mm/minute. After the welding, tensile test was carried out, to find that the rupture occurred at the welded part, under ultimate load 29.3 kN (2,992 kgf). By dividing the ultimate load by cross-sectional area, tensile strength of 488 N/mm² (49.8 kgf/mm²) was obtained. This value surpasses that of carbon steel S20C (400 N/mm² or more), that of titanium (340 N/mm² or more), and thus the value was close to that of tensile strength of SUS304 (520 N/mm² or more). Consequently, it was found that laser welding with the combination of the above-mentioned nickel beryllium alloy with SUS304 realizes sufficient strength.

[0031] According to the foregoing embodiment, in which the head 2 is constructed by combining two metallic members consisting of the head body 11 formed with the hosel 3, said head body 11 being made from SUS304 stainless steel which is comparatively easy to process, and a face plate 14 made from high-strength and comparatively expensive nickel beryllium alloy, said two metallic members being welded to each other by laser beam welding. Accordingly, the inclination angle of the hosel 3, i.e., the relative angel of the axis of the shaft 4 to the face 5 or loft/lie angle of the head 2 can be comparatively easily controlled. Further, as the face plate 14 is made from such a high strength material that the flight distance of golf balls can be elongated. Specifically, as great strength can be obtained through the heat treatment of the nickel beryllium alloy, it is possible to make the face 5 or the face plate 34 thinner, thus saving a certain amount of the weight, which is then able to be distributed to other peripheral portions such as the sole 8, whereby the center of gravity of the head 2 can be positioned still backwards. On the other hand, stainless steel such as SUS304 has several advantages such as good corrosion resistance and moderate prices, although it is inferior to nickel beryllium alloy in respect of strength. By combining these two metals to construct the head 2, the improved flight distance of golf balls as well as the enlarged sweet spot for striking balls, can be realized.

[0032] Further, as the two kinds of metals, i.e., nickel beryllium alloy and stainless steel such as SUS304, are welded to each other by means of the laser processing machine, the joining configurations and dimensions of the face plate 14 relative to the head 2 are subjected to little limitation, thus leading to enhanced degree of freedom in designing the head, whereby high-performance head can be obtained. Furthermore, the kinds of useable materials are subjected to less limitation than by plastic processing. Moreover, costs can be reduced without increasing processing time and steps. Still also, constant finish can be obtained, without clearances between the joining surfaces, thus improving appearance of the head.

[0033] Hereinafter will be described second and third embodiments of the invention with reference to FIGS. 3-4, 5-6, respectively. The same portions as those described in the foregoing embodiment will be designated by the same reference numerals, and their repeated detailed descriptions will be omitted.

[0034] In the second embodiment, a head body 21 made from nickel beryllium alloy has the face 5 formed on a front, the heel 6 formed on a lower part thereof, the top 7 formed on a top of a second side of the head 21, and the sole 8 formed on a bottom thereof, respectively. A hosel member 22 which is made from stainless steel such as SUS304, provided for connecting the shaft thereto, is fixed to the upper part of the heel 6 by means of welding. The hosel member is approximately cylinder-shaped, having a plane lower surface 23, which is abutted against a receiving plane surface 24 formed on the upper part of the heel 6, and then welded together.

[0035] Next, a method for manufacturing the head 2 will be described.

[0036] First, high strength nickel beryllium alloy is forged to form the head body 21, while stainless steel such as SUS304 is forged to form the hosel member 22. Thereafter, the lower surface 23 of the hosel member 22 is abutted against the receiving surface 24 of the head body 21, and then the processing head 25 of the laser processing machine is brought close to the boundary between the lower surface 23 and the receiving surface 24, thereby irradiating the same with laser beam, whereby both members are securely fixed to each other through the welding part 26. Incidentally, in the above manufacturing method, the method of laser welding and its test result are the same as those in the first embodiment.

[0037] According to the second embodiment, in which the head 2 is constructed by combining the head body 21 made from high strength nickel beryllium alloy and the hosel member 22 made from SUS304 stainless steel which is comparatively easy to process, said two metallic members being welded to each other by laser beam welding. Accordingly, as the face 5 is made from such a high strength material, the flight distance of golf balls can be elongated. Also, as the processing of the hosel 22 becomes relatively easier, the above-mentioned loft/lie angle of the head 2 can be comparatively easily controlled.

[0038] Further, as the two kinds of metals, i.e., nickel beryllium alloy and stainless steel such as SUS304, are welded to each other by means of the laser processing machine, the joining configuration and dimension of the face plate 14 relative to the head 2 are subjected to little limitation, thus leading to enhanced degree of freedom in designing the head, whereby high-performance head can be obtained. Furthermore, the kinds of useable materials are subjected to less limitation than by plastic processing. Moreover, costs can be reduced without increasing processing time and steps. Still also, constant finish can be obtained, without clearances between the joining surfaces, thus improving appearance of the head.

[0039] Referring to FIGS. 5 and 6 showing the third embodiment of the invention, the head 2 is constructed of: a head body 30, having the hosel 3, face 5, heel 6, top 7 and sole 8 formed thereon, and a laterally elongated recess 30B formed on a rear surface 30A thereof, said head body being made from a metal of comparatively small specific gravity such as titanium alloy, aluminum or aluminum alloy; and a balance weight 11 made from a denser material than that of the said head body 30, such as SUS304 stainless steel, iron, copper or copper alloy, said balance weight 11 being fitted into the recess 30B and fixed thereto by welding. The rear surface 30A of said head body 30 is formed flush with a rear surface 31A of said balance weight 11 so as to provide a smooth continuous surface.

[0040] Next, a method for manufacturing the head 2 will be described.

[0041] First, the aforesaid head body 30 is formed by forging. Then, the recess 30B is formed by forging, machining or grinding. Likewise, the aforesaid balance weight 31 is forged so as to be shaped into a configuration approximately corresponding to that of the recess 30B. Thereafter, the balance weight 31 is fitted into the recess 30B, and then the processing head 32 of the laser processing machine is brought close to the boundary between the recess 30B and the balance weight 31 to irradiate the same with laser beam, thereby joining them together, through a laser welding portion 33.

[0042] According to the third embodiment of the invention, the head 2 is constructed of the head body 30 with the face 5, said head body 30 being made from a metal of comparatively small specific gravity; and the balance weight 11 made from a denser metal than that of the head body 30, whereby the sweet spot can be enlarged by disposing the center of gravity of the head 2 backwards.

[0043] Further, as the two kinds of metals are welded to each other by means of the laser processing machine, the joining configuration and dimension of the balance weigh 31 in the head 2 are subjected to little limitation, thus leading to enhanced degree of freedom in designing the head, whereby high-performance head can be obtained. Furthermore, the kinds of useable materials are subjected to less limitation than by plastic processing. Moreover, costs can be reduced without increasing processing time and steps. Still also, constant finish can be obtained, without clearances between the joining surfaces, thus improving appearance of the head.

[0044] Incidentally, the present invention should not be limited to the foregoing embodiments, but may be variously modified within a scope of the invention. For example, the aforesaid combination of at least two kinds of metals may be suitably modified. For a metal of the comparatively small specific gravity, aluminum, aluminum alloy, titanium or titanium alloy may be used in place of nickel beryllium alloy, while for a metal of the comparatively large specific gravity, carbon steel, copper, copper alloy may be used in place of SUS304 stainless steel. 

What is claimed:
 1. A golf club, having a head with a shaft connected thereto, wherein said head is constructed by combining at least two components each of which being made from a different metal, said components being joined together by welding.
 2. A golf club, having a head with a shaft connected thereto, wherein said head is constructed of a head body with a face and a face plate corresponding to the face, wherein said head body and said face plate are made from different metals, respectively, and are joined together by welding.
 3. A golf club, having a head with a hosel and a shaft connected with the hosel, wherein said head is constructed of a head body and a separate hosel member, corresponding to said hosel, wherein said head body and said hosel member are made from different metals, respectively, and are joined together by welding.
 4. A golf club, having a head with a shaft connected thereto, wherein said head is constructed of a head body with a face and a separate balance weight, wherein said head body and said balance weight are made from different metals, respectively, and are joined together by welding.
 5. A golf club according to claim 1 , wherein said welding is laser welding, using a laser processing machine.
 6. A golf club according to claim 2 , wherein said welding is carried out by laser beam welding, using a laser-processing machine.
 7. A golf club according to claim 3 , wherein said welding is carried out by laser beam welding, using a laser-processing machine.
 8. A golf club according to claim 4 , wherein said welding is carried out by laser beam welding, using a laser-processing machine.
 9. A golf club according to claim 2 , wherein said head body is formed by forging SUS304 stainless steel, while said face plate is formed by forging nickel beryllium alloy.
 10. A golf club according to claim 3 , wherein said head body is formed by forging nickel beryllium alloy, while said hosel is formed by forging SUS304 stainless steel.
 11. A golf club according to claim 4 , wherein said head body is formed by forging a metal of comparatively small specific gravity, such as titanium, titanium alloy, aluminum or aluminum alloy, while said balance weight is formed by forging a metal of comparatively large specific gravity, such as SUS304 stainless steel, copper, copper alloy. 